Table of Contents
- What is Diroximel Fumarate?
- How Does It Work?
- What Conditions Does It Treat?
- Clinical Studies
- Safety and Side Effects
- Administration and Dosage
- Pregnancy and Breastfeeding
- Comparison with Other Treatments
What is Diroximel Fumarate?
Diroximel fumarate is a medication used to treat multiple sclerosis (MS). It’s also known by its brand names Vumerity and BIIB098[1]. This drug belongs to a class of medications called disease-modifying therapies (DMTs), which are designed to slow down the progression of MS and reduce the frequency of relapses[2].
How Does It Work?
Diroximel fumarate works by being converted in the body to its active form, called monomethyl fumarate (MMF)[3]. While the exact mechanism isn’t fully understood, it’s believed that MMF helps reduce inflammation in the nervous system and may protect nerve cells from damage. This action helps to slow down the progression of MS and reduce the frequency of relapses[2].
What Conditions Does It Treat?
Diroximel fumarate is primarily used to treat relapsing forms of multiple sclerosis (MS) in adults. This includes:
- Relapsing-remitting MS (RRMS): The most common form of MS, characterized by periods of symptom flare-ups followed by periods of recovery.
- Active secondary progressive MS (SPMS): A form of MS that develops after RRMS, where symptoms steadily worsen over time, with or without relapses.
- Clinically isolated syndrome (CIS): The first episode of neurological symptoms that lasts at least 24 hours and may or may not develop into MS[1].
Clinical Studies
Several clinical trials have been conducted or are ongoing to evaluate the effectiveness and safety of diroximel fumarate:
- The EXPERIENCE-US study is investigating how well patients stick to their treatment regimen (persistence) when using diroximel fumarate in real-world settings. It’s also looking at the drug’s safety, tolerability, and effectiveness in reducing relapses and improving cognitive function[1].
- Similar studies, like EXPERIENCE-CA+IL, are being conducted in Canada and Israel to assess the drug’s performance in different populations[2].
- A study in the Asia-Pacific region is evaluating the safety, tolerability, and how the body processes diroximel fumarate (pharmacokinetics) in East Asian patients with MS[4].
Safety and Side Effects
Like all medications, diroximel fumarate can cause side effects. Common side effects may include:
- Gastrointestinal (GI) issues: Such as nausea, diarrhea, or stomach pain. These are often mild and tend to decrease over time[1].
- Flushing: A temporary warmth, redness, or itching of the skin.
- Decreased white blood cell count: Specifically, a reduction in lymphocytes, which are important for fighting infections[1].
Serious side effects are rare but can include severe allergic reactions or serious infections. Your doctor will monitor your blood cell counts regularly while you’re taking this medication[1].
Administration and Dosage
Diroximel fumarate is taken orally in the form of delayed-release capsules. The typical starting dose is 231 mg twice daily for 7 days, followed by the maintenance dose of 462 mg twice daily[4]. It’s important to take the medication as prescribed by your doctor and not to stop or change your dosage without consulting them first.
Pregnancy and Breastfeeding
If you’re pregnant, planning to become pregnant, or breastfeeding, it’s crucial to discuss the use of diroximel fumarate with your healthcare provider. Studies are ongoing to better understand the effects of this medication during pregnancy:
- The Vumerity Pregnancy Exposure Registry is collecting data on pregnancy outcomes in women exposed to diroximel fumarate during pregnancy[5].
- Another study is assessing pregnancy outcomes in women exposed to diroximel fumarate compared to other MS treatments or no treatment[6].
Comparison with Other Treatments
Diroximel fumarate is one of several oral medications available for treating MS. It’s closely related to another drug called dimethyl fumarate (Tecfidera), but it’s designed to cause fewer gastrointestinal side effects[7]. Some studies are comparing diroximel fumarate to other MS treatments:
- The STATURE study is comparing the treatment burden and medication adherence across six oral MS treatments, including diroximel fumarate[8].
- Another study is comparing the long-term safety of Vumerity (diroximel fumarate) and Tecfidera (dimethyl fumarate)[7].
Your healthcare provider will consider various factors, including your specific form of MS, other health conditions, and personal preferences, when deciding if diroximel fumarate is the right treatment for you.




